1. Field of the Invention
This invention relates to an apparatus for continuously producing pleated semipermeable membrane elements each enclosed in a pressure-resistant container for use in the separation, concentration and purification of fluids.
2. Description of the Prior Art
Precision filtration, ultrafiltration, reverse osmosis and like processes, which utilize membranes, have found wide use for the separation, purification and concentration of fluids, for the production of water, and for the treatment of industrial effluents. Semipermeable membranes useful for these applications are divided basically into four types: tubular, spirally wound, hollow fiber, and plate-and-frame. Of these types, the spirally wound type has been used most extensively. Besides these, pleated semipermeable membrane elements have been introduced into use in recent years (U.S. Pat. No. 3,266,223, and U.S. patent application Ser. No. 906,076, filed May 15, 1978).